1. Field of the Invention
The present invention relates to a terminal box having a terminal board for connecting a tab of a solar cell panel to a power line.
2. Description of the Related Art
Generally, a solar cell module includes a plurality of solar cell panels, with a terminal box being mounted on the back face of each solar cell panel. This terminal box includes a terminal board for establishing conduction between the tab of the solar cell panel and the external power line. Hence, it is necessary for a portion of the terminal board to be contacted to the tab of the solar cell panel.
Various arrangements are possible for the tab of the solar cell panel, including a mode of arrangement in which the tab is mounted on the back face of the solar cell panel (this will be referred to as “the first mode of arrangement” hereinafter), another mode of arrangement in which the tab is disposed inside the solar cell panel adjacent its back face (this will be referred to as “the second mode arrangement” hereinafter). For contacting the tab arranged as above with the terminal board, it is needed to ensure that the terminal board projects from the main body of the terminal box.
On the other hand, if the amount of projection of the terminal box is inappropriate, the terminal box may fail to contact the tab, thus resulting in conduction failure. Conversely, if the projection amount is too large, this may cause the terminal box to “float off”, i.e. to detach from, the back face of the solar cell panel, thus forming a gap that allows intrusion of rainwater or the like therethrough to the inside of the terminal box. For this reason, appropriate setting is required for the projection amount of the terminal box according to varied specifications of the solar cell panel.
However, the appropriate projection amount of terminal board differs according to the specification of the solar cell panel. The appropriate projection amount may differ according also to the difference of the above-described mode of arrangement. For this reason, it is necessary to adjust the projection amount of the terminal board according to the specification of the solar cell panel employed. However, this adjustment is troublesome and increases the cost of installment. Further, the terminal box too needs to be configured to allow adjustment of the projection amount of terminal board. This leads to increase in the manufacture cost of the terminal box disadvantageously. Alternatively, it is conceivable to prepare and employ terminal boards set with differing projection amounts. This is also disadvantageous since it invites manufacture cost increase of the terminal box again.
In an attempt to overcome the above problem, WO 2010/067466 discloses a terminal box configured such that spring-like characteristics is provided to the leading end of the terminal board disposed substantially parallel with a solar cell panel. Japanese Patent Application National Transfer Publication No. 2011-503884 discloses a terminal box wherein an elastic part is formed in an intermediate portion of the terminal board. With these arrangements, reliable connection between the terminal board and the tab can be ensured by the spring-like property characteristics of the terminal board if a relatively large projection amount of the leading end of the terminal board is set in advance. Further, as a pressing force resulting from the connection is absorbed by the spring-like characteristics of the leading end of the terminal board, the floating phenomenon of the terminal box can be prevented also.
However, with the terminal boxes disclosed in WO 2010/067466 and Japanese Patent Application National Transfer Publication No. 2011-503884, because an elastic part is formed at the leading end or intermediate portion of the terminal board, the adjustability of the projection amount of terminal board is not so large. Also, with the terminal box disclosed in Japanese Patent Application National Transfer Publication No. 2011-503884, since an elastic part is formed upwardly of a soldering zone (a portion to be soldered to the tab of the terminal board), the elastic part may hinder the soldering operation.
The present invention has been made in view of the above-described state of the art and its object is to provide a terminal box that allows easy adjustment of the projection amount of the terminal board.